1. Field of the Invention
The present invention relates to image encoding and/or decoding, and more particularly, to a color image residue transform and/or inverse transform method and apparatus, and a color image encoding and/or decoding method and apparatus using the same.
2. Description of the Related Art
Generally, when a color image is encoded, color transform is first performed and then encoding is performed. There are many types of color coordinate systems, and among them, an RGB coordinate system can be picked up as a basic coordinate system. For encoding, an RGB image is transformed into a YCbCr image, a luminance component and a color component are separated, and then, encoding is performed. If thus encoding is performed, the encoding efficiency is enhanced, because there is much redundancy between respective color components and the redundancy has been removed through the transform. In particular, an integer transform method using a lifting method has been researched recently, and, for example, there is a method, YCoCg-R, developed by Microsoft.
Meanwhile, when the thus transformed image is encoded, a process removing redundancy in each component through spatiotemporal prediction is performed and as a result, a residue image is obtained. In H.264/MPEG-4 pt. 10 AVC Standardization technology of Joint Video Team (JVT) of ISO/IEC MPEG and ITU-T VCEG (“Text of ISO/IEC FDIS 14496-10: Information Technology—Coding of audio-visual objects—Part 10: Advanced Video Coding”, ISO/IEC JTC 1/SC 29/WG 11, N5555, March, 2003), whose standardization has been proceeding recently, an encoding efficiency is enhanced by performing spatial and temporal prediction encoding in a variety of ways. However, when spatiotemporal prediction is performed between respective color components in an identical method, there exists much redundancy between residue images of respective color components.